首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Sarcomas are rare malignant tumors with a large variety of histologic subtypes. The surgical approach depends more on the histologic grade, the size and the site of the tumor. Radiologic diagnosis relies predominantly on MR-imaging. Discernible improvements have taken place in soft tissue sarcoma patient survivorship and quality of life over the past 20 years, with overall 5-year survival currently at approximately 50-80%. The place of surgery in the treatment of soft-tissue sarcoma is defined in the light of a review of the recent literature. Radical surgical resection is the mainstay of therapy. Local recurrence is the most common type of failure. Local recurrence is resectable and limb preservations possible in the majority of patients. Survival after treatment of local recurrence is determined mainly by the grade and secondarily by the size of the tumor. The essential risk factor for local recurrence is the quality of surgical resection, defined by the definitive resection margins. A lateral safety margin of 5 cm and of 2 cm to the depth should be respected. In sarcoma of the extremity the compartment is defined based on clinical, radiographic, histopathologic and operative findings. The use of muscle flaps to fill the surgical defects can improve the functional result and reduce the complication rate. Only about 5% of the patients need amputation. Evaluation of functional results must be based on objective criteria. In retroperitoneal sarcoma the significant factors for determining prognosis are grade and completeness of exzision. Multidisciplinary treatment according to common protocols is essential. Shifts in treatment have taken place over the past decade, from single-modality treatment involving radical surgery with compartment resection to sophisticated limb-salvage strategies combined with radiation therapy. In case of inadequate surgery e.g. in a large tumor with positive margins in high-grade soft tissue sarcomas the addition of radiotherapy can improve local control, but cannot ensure that obtained by adequate surgery. Patients with large (greater than 5 cm), high grade soft tissue sarcoma are at high risk for distant recurrence and disease-related mortality. Investigations of combined modality therapy with newer chemotherapy agents and dose intensification treatment strategies are warranted.  相似文献   

2.
BACKGROUND: The management of locally recurrent extremity soft tissue sarcoma remains challenging. This study was undertaken to evaluate the long-term outcome after therapy for isolated locally recurrent soft tissue sarcoma (STS) of the extremity. METHODS: Between January 1, 1980, and December 31, 1990, 52 patients were treated at The University of Texas M. D. Anderson Cancer Center for locally recurrent extremity STS. The records of the subset of these patients (n = 36) with isolated local recurrence were examined to document clinicopathologic and treatment factors and to evaluate outcome using the end points of local recurrence-free, recurrence-free, and overall survival. RESULTS: Limb-sparing conservative surgery was possible in 24 patients (75%). Twelve (33%) of 36 patients were treated by surgery alone, 23 patients (64%) were treated with combined modality therapy (surgery plus radiation and/or chemotherapy), and 1 patient had radiotherapy only. Sixteen (44%) of 36 patients had no further recurrence of any type at a median follow-up of 58 months (range, 4 to 173 months). The 5-year actuarial local recurrence-free, recurrence-free, and overall survival rates were 72%, 45%, and 77%, respectively. CONCLUSIONS: Limb-sparing conservative surgery is possible in the majority of patients with isolated locally recurrent STS. Durable local control can be established with individualized local treatment strategies. These results support aggressive multimodality limb-sparing treatment approaches for these patients.  相似文献   

3.
BACKGROUND: The aim of this study was to determine how and by which specialties patients with soft tissue sarcoma are investigated and treated within a single large health region and with what outcomes and implications for resource uptake. METHODS: By retrieving the records of 377 patients with primary soft tissue sarcoma treated in the South-East Thames Region between 1986 and 1992, the presentation, investigation, treatment and outcome were compared with defined criteria for optimal management. Patient management was assessed and compared between specialties and districts on the basis of outpatient time, appropriate use of radiological investigations and preoperative biopsy, type of surgery, content of the pathology report and the incidence of local recurrence, metastasis and death over a mean follow-up period of 2.5 years. RESULTS: Most patients (53.6 per cent) were treated by general surgeons, irrespective of tumour location. Overall only 21.3 per cent of patients were investigated optimally with wide variation among specialties. Only 60.0 per cent were treated adequately (wide excision or surgery with radiotherapy). Uptake of adjunctive therapy and follow-up were variable. Outcome was poorer in patients having a marginal excision and recurrence. CONCLUSION: Investigation and management of many patients with soft tissue sarcoma was both variable and suboptimal. This has implications for patient care, resource uptake and costs. As has been amply demonstrated elsewhere, patients with sarcoma are more appropriately managed in specialist centres.  相似文献   

4.
Soft tissue sarcomas are relatively rare tumors with an annual incidence of 5000 to 6000 in the United States. The primary therapy is surgical resection with an adequate margin of normal tissue. For patients at high risk local control is improved with postoperative adjuvant radiation. Local recurrence rates vary depending on the anatomic site. In extremity lesions one third of patients will have locally recurrent disease with a median disease-free interval of 18 months. Treatment results for extremity local recurrence may approach those for primary disease. Isolated pulmonary metastases may be resected with 20% to 30% 3-year survival rates. Patients with sarcomas in other sites present similar but more difficult problems in terms of local control and management of disseminated disease. Patients with unresectable pulmonary metastases or extrapulmonary metastatic sarcoma have a uniformly poor prognosis and are best treated with systemic chemotherapy.  相似文献   

5.
BACKGROUND: Synovial sarcoma is the third most common pediatric soft tissue tumor. It requires an aggressive approach to achieve a cure. However, optimal treatment modalities adapted to disease extension and histologic variants have not been determined because there is little information about prospectively treated patients. METHODS: A multicenter trial for soft tissue sarcomas (Protocol CWS 81) was conducted in West Germany between 1981-1985, and 31 patients with synovial sarcoma were registered. Treatment included multiagent chemotherapy and irradiation after initial tumor excision or biopsy. The male-female ratio in this group was 1:1.6 with a median age of 14 years (range, 1-19 years). The median follow-up time after diagnosis was 101 months (range, 77-131 months). RESULTS: The overall event-free survival (EFS) for patients with synovial sarcoma was 74.2% at 5 years. Group I-II tumors had a significantly better prognosis than those in Group III-IV (EFS at 5 years 84.4% and 58.3%, respectively; P = 0.024). Small tumors (< 5 cm) responded better than larger tumors (> or = 5 cm; EFS, 93% versus 58%; P = 0.029). Synovial sarcoma involved the extremities in 28 patients who had a better outcome compared with those with extremity rhabdomyosarcoma in this study (EFS for Group I-IV was 82% versus 24%, P = 0.001). CONCLUSIONS: The results appeared superior to previous experience using radical surgery alone and suggested that after initial, nonmutilating surgery, adjuvant chemotherapy, and irradiation contributed to the improved long-term survival.  相似文献   

6.
OBJECTIVE: To determine whether neoadjuvant chemotherapy and radiotherapy for bony sarcomas extending into soft tissues would allow limb salvage yet maintain local disease control. DESIGN: A prospective cohort study. SETTING: A university-affiliated cancer centre in Alberta. PATIENTS: All patients with potentially curable, widely infiltrating bony sarcomas of the extremity without neurologic deficit, referred to the centre in the 6 years from January 1984 to December 1990. There were 11 patients; 1 did not complete the protocol. The mean follow-up was 24 months. INTERVENTIONS: Adriamycin (doxorubicin) was infused for 3 days at a rate of 30 mg/d. A few days later radiotherapy was given 5 days a week for 10 doses at a rate of 3.0 Gy per dose. Four to 5 weeks later the tumour was excised surgically, with placement of a bone allograft or prosthesis, allowing a 1-cm margin of healthy soft tissue and a 5-cm margin of healthy bone and marrow cavity whenever possible. MAIN OUTCOME MEASURES: Need for limb amputation, infectious complications, recurrence of local or regional disease. RESULTS: One patient underwent amputation after fracture through the tumour site. There were two postoperative infections, one acute and one chronic. All patients had full neurologic function of the distal limb. There was no local or regional recurrence of disease. CONCLUSION: Neoadjuvant chemotherapy followed by radiotherapy and tumour excision provides control of aggressive local bone sarcomas while maintaining limb integrity.  相似文献   

7.
External beam radiation may be given either before or after excision of a primary soft tissue sarcoma. This study was undertaken to determine whether or not the timing of radiotherapy was associated with any difference in either local control, survival, or incidence of complications. The files of 112 patients with a primary, nonmetastatic, extremity soft tissue sarcoma, treated with limb salvage surgery and irradiation were evaluated. Data regarding tumor stage, grade, site, surgical margin, dosage and timing of radiotherapy, treatment complications, disease relapse, and relapse-free survival (RFS) were analyzed. Kaplan-Meier lifetable analysis was used to determine survival estimates. There was no significant difference in the 5-year RFS between patients receiving radiotherapy (RT) preoperatively versus postoperatively; 56 +/- 15% and 67 +/- 12% (P = 0.12, Mantel-Cox), respectively. There was no significant difference in the overall survival between patients receiving RT preoperatively versus postoperatively; 75 +/- 15% and 79 +/- 11% (P = 0.94), respectively. Actuarial local control at 5 years for preoperative versus postoperative RT patients was not statistically different; 83 +/- 12% versus 91 +/- 8% (P = 0.41), respectively. Wound complications were more frequent in preoperative RT patients (31%) compared to postoperative RT patients (8%) (P = 0.0014, chi-square). Preoperative irradiation was not associated with any benefit in terms of relapse-free survival, overall survival or actuarial local control in this series. A higher incidence of major wound complications was found among patients treated with preoperative irradiation. We recommend that patients with a resectable extremity soft tissue sarcoma be treated with postoperative irradiation, reserving preoperative irradiation for those situations in which either the tumor is initially thought to be unresectable or the original tumor boundaries are obscured.  相似文献   

8.
PURPOSE: To evaluate the disease-free and overall survival of pediatric patients with nonrhabdomyosarcoma soft-tissue sarcomas. METHODS: We retrospectively analyzed the records of 67 pediatric patients with a diagnosis of nonrhabdomyosarcoma soft tissue sarcoma treated with curative intent between 1970 and 1992. Median follow-up time for the 52 survivors was 120 months (range, 7 to 277 months). Fifty-nine patients received external beam radiotherapy, in a median dose of 5400 cGy (range, 1800 to 6660 cGy.) All patients underwent an initial surgical procedure. Eighteen patients had gross residual disease, and 15 had gross total excision with microscopic residual disease or positive margins. Adjuvant chemotherapy was administered to 44 patients (65%). RESULTS: The actuarial 10-year freedom from progression or recurrence and overall survival rates were 76% and 75%, and the 20-year rates were the same. Of 18 patients with gross residual disease, 9 (50%) had local progression and 6 died of local-only disease. By contrast, only one patient with microscopic residual disease who received postoperative radiotherapy had a local recurrence. The disease-free survival rate also correlated with histologic grade. CONCLUSIONS: As with adult soft tissue sarcomas, gross residual disease predicts local failure. Our results suggest that pediatric patients with soft tissue sarcomas treated with surgery and postoperative radiotherapy generally have a favorable overall survival rate.  相似文献   

9.
Because there is evidence for an active immunologic response against sarcoma, a clinical trial of adjuvant immunotherapy using bacillus Calmette-Guérin (BCG) and tumor cell vaccine was begun. Eleven of 18 patients with localized soft tissue sarcoma who received immunotherapy are free of disease, compared to only 5 of 15 treated by operation alone who are free of disease. Furthermore, immunotherapy also prolonged the median disease-free interval from 7.3 months to 15 months in the patients who experienced recurrence of their disease.  相似文献   

10.
Malignant melanoma of soft parts, also termed clear cell sarcoma (CCS), is a rare malignancy of neural crest origin which is different from cutaneous malignant melanoma. Although a translocation involving chromosomes 12 and 22 is characteristic of clear cell sarcoma and not malignant melanoma, there are a paucity of methods to differentiate the two. Therefore, a study of microsatellite instability (MIN) was undertaken to determine if mechanisms of DNA mismatch repair can differentiate these malignancies. MIN has been described in a variety of malignancies including 25% of malignant melanomas. Paraffin-embedded neoplastic and non-neoplastic cells were obtained from 11 individuals (five males; six females; age range from seven to 60 years) with CCS. Isolated DNA was PCR amplified at 17 separate microsatellite loci using radioactive-labeled primers. Tumor tissue was compared to normal tissue for each analysis. No MIN was detected. Loss of heterozygosity was detected in only one patient at a single locus (IFNA). The lack of MIN in clear cell sarcoma further defines the distinction between this tumor and malignant melanoma. Clinically, local recurrence and metastasis were indicators of poor outcome. The size of the tumor was not a significant prognostic indicator. Local recurrence, satellitosis, or nodal metastasis was not proven to be uniformly fatal. Utilization of chemotherapy and/or radiation demonstrated no obvious survival advantage. The histologic parameters of mitotic rate and the presence of necrosis were not prognostic. Limb-preserving surgical procedures were as effective as amputation for local disease control. The actuarial survival rate was calculated to be 48% at five years.  相似文献   

11.
OBJECTIVE: To identify any clinical and pathologic features of treatment modalities that are predictive of outcome in patients with epithelioid sarcoma, a rare slow-growing soft tissue tumor most commonly occurring in the distal extremities of young adults. DESIGN: We reviewed the institutional files for cases of epithelioid sarcoma for the period 1956 to 1991 and analyzed the effect of various factors on survival. MATERIAL AND METHODS: Fifty-five cases of epithelioid sarcoma were found, and the relevant clinical, pathologic, treatment, follow-up, and outcome features were assessed. RESULTS: All tumors were treated initially by operative resection. The recurrence rate progressively decreased with increasing aggressiveness of the initial operation; however, no difference was noted in metastatic rate. Overall, the recurrence rate was 38% and the metastatic rate was 47%. At the end of a mean follow-up of 102 months, 69% of patients had no evidence of disease, 27% had died of the disease, and 4% were alive with disease. Increasing tumor size, necrosis of more than 30%, and vascular invasion correlated significantly with a worse prognosis. CONCLUSION: Epithelioid sarcoma should be considered a malignant neoplasm with a significant potential for aggressive behavior, and close follow-up of affected patients should be maintained for many years. Initial treatment should be aggressive in an attempt to prevent recurrence.  相似文献   

12.
BACKGROUND: To the authors' knowledge there are few published series of malignant vascular tumors in patients age < or = 21 years. METHODS: The authors retrospectively documented the clinical presentation, pathology, treatment, and outcome of patients age < or = 21 years with malignant vascular tumors treated between 1970-1995 at Memorial Sloan-Kettering Cancer Center. The histologic sections were rereviewed to confirm the diagnosis. RESULTS: Four patients were identified with angiosarcoma and two with malignant hemangioendothelioma. Five patients were female and one was male; the median age at diagnosis was 11.8 years (range, 8 months-21 years). The tumor involved the skin in one patient, soft tissue in one patient, bone in two patients, and internal organs in two patients. One patient had associated diffuse angiomatosis and another had the Klippel-Trenaunay-Weber syndrome. This patient received prior radiation therapy to the primary site with the subsequent development of a vascular sarcoma. None of the patients had distant metastases at diagnosis. Resection was attempted in five patients and completed in four. Chemotherapy alone was given to three patients whereas radiation therapy alone and radiation plus chemotherapy were administered to one patient each. The median follow-up was 4.9 years (range, 1 month-12 years). There were three deaths from progressive disease and two deaths from locoregional recurrences. Reexcision and radiotherapy controlled one local recurrence. Another patient developed recurrence to regional lymph nodes and further dissemination. The primary tumor in all three survivors was excised completely whereas two of the three patients who died of progressive disease underwent an incomplete excision or biopsy alone. CONCLUSIONS: Malignant vascular tumors are rare in the first two decades of life and when they do occur are very aggressive. Complete resection is curative for patients with localized lesions.  相似文献   

13.
JM Serletti  AJ Carras  RJ O'Keefe  RN Rosier 《Canadian Metallurgical Quarterly》1998,102(5):1576-83; discussion 1584-5
Limb salvage has been achieved for patients with sarcoma by means of compartmental resection, soft-tissue reconstruction, and adjuvant therapy without increased rates of local recurrence, metastasis, or mortality. Despite the prevalence of limb salvage procedures in the treatment of these tumors, relatively little information has been published regarding late functional results in these reconstructed extremities. This study reports on the functional outcome for soft-tissue reconstruction for limb salvage in patients with sarcoma. Over the past 6 years, 28 patients were treated for sarcomas of the extremity in which soft-tissue reconstruction was needed for complete limb salvage. The mean age of these patients was 48 years (range, 14 to 83 years); there were 14 male and 14 female patients. Of the 28 sarcomas, 23 cases involved the lower extremity and 5 cases were in the upper extremity. Reconstruction was performed primarily in 12 patients; 16 reconstructions were performed secondarily because of wound complications after initial extirpation. Adjuvant radiation therapy was administered either preoperatively or postoperatively in all cases. Of the 33 reconstructive procedures performed in these 28 patients, 16 involved free flaps and 17 involved local flaps. All patients achieved initial limb salvage after the reconstructive procedure(s). Mean follow-up was 38 months. Twenty patients were available for the evaluation portion of the study. Two patients had delayed amputations: one for recurrent disease and another for osteoradionecrosis. Two patients died before beginning the examination process: one patient from the sarcoma and another patient from colon cancer. Twenty of the remaining 24 patients agreed to participate and were examined using the Enneking outcome measurement scale. Patients were examined for range of motion, deformity, stability, pain level, strength, functional activity, and emotional acceptance and assigned a numerical score for each category. Based on this, an overall rating of excellent, good, fair, or poor was assigned. Nine patients (45 percent) achieved an overall rating of excellent, five patients (25 percent) achieved a rating of good, and six patients (30 percent) achieved a fair score. None had received a rating of poor. There were no differences in the results obtained comparing upper versus lower extremity, immediate versus delayed reconstruction, or reconstructions performed with a free flap versus a pedicled flap. This study supports the continued use of soft-tissue reconstruction for limb salvage in sarcoma surgery with good to excellent late functional results obtained in the majority of patients.  相似文献   

14.
BACKGROUND: Soft tissue sarcomas of the hands and feet present a challenge for limb-preserving resections. METHODS: A retrospective review of 19 patients with sarcomas of the hand or foot was done. Wide or local excision was performed in 14 patients (74%), and amputation in 5 patients (26%). Of the latter group, three amputations involved a digit or toe, and two (10%) were major amputations (one Syme amputation and one below-knee amputation). When the minimum surgical margin was narrow (1 to 2 mm), adjuvant radiation was given postoperatively (n = 4). RESULTS: Local recurrence was observed in four patients (21%). Two of these required an amputation for local control. Local recurrence was observed in one of four patients (25%) treated with marginal resection and radiation and three of 15 (20%) of those with resection alone. CONCLUSIONS: A sizable percentage (37%) of patients with soft tissue sarcomas of the hand and foot ultimately required an amputation, although often the amputation was a minor one involving only a toe or a digit. Limb preservation was successful in the majority of patients (63%). The local recurrence rate was 21%, which may be improved with more frequent use of adjuvant therapy. The 5-year survival rate was 82%, which is better than that usually quoted for overall extremity soft tissue sarcomas.  相似文献   

15.
Although malignant fibrous histiocytoma represents the most common soft tissue sarcoma in adults, its origination in visceral organs is very unusual and the liver is an exceptional site of involvement, with only 22 cases reported in the last 12 years. This controversial tumour, first described in 1964, probably originates from undifferentiated mesenchymal cells and has five different histological subtypes: storiform pleomorphic, myxoid, giant cells, inflammatory and angiomatoid. We describe herein the rather variable CT findings of three malignant fibrous histiocytomas of the liver and discuss their differential diagnosis.  相似文献   

16.
BACKGROUND: Recurrent melanoma of the extremity has been treated by local excision, systemic chemotherapy, amputation, or a combination of these approaches. Hyperthermic isolated limb perfusion (HILP) provides a method of limb preservation through isolation, allowing the administration of chemotherapy in higher doses than is possible through systemic treatment. METHODS: An experimental group of 59 HILP patients with melanoma recurrences of the extremity was studied prospectively. A control group of 248 melanoma patients with similar recurrences was excluded from HILP because their recurrences were in non-extremity locations. The experimental group underwent HILP and excision; the control group had excision only. The experimental procedure consisted of vascular isolation of the affected extremity and a 1-hour perfusion with melphalan. Temperatures were maintained at 40 degrees C in the perfusion circuit. RESULTS: The HILP patients had a lower rate of locoregional recurrence (P=.028) and demonstrated increased survival (P=.026) compared to the control group. In multivariate regression analysis, which included age, ulceration and thickness of the primary, and the treatment variable of perfusion, age (P=.02) and perfusion for the treatment of recurrence (P=.006) were significant predictors of survival. CONCLUSIONS: HILP improves prognosis by sterilizing the treated extremity, controlling locoregional disease, and perhaps preventing metastasis, thus having a positive impact on overall survival.  相似文献   

17.
18.
In order to detect skeletal metastases in patients with Ewing's sarcoma, bone scanning is commonly used. However, little information is available about the scintigraphic aspects of the primary Ewing's sarcoma during non-surgical treatment and follow-up. We studied retrospectively the significance of bone scintigraphic findings at the primary tumor site of 58 patients with a Ewing's sarcoma. These patients had chemotherapy and radiotherapy. At presentation 53/58 patients showed an increased tracer uptake at the primary tumor site while 5 patients with a pelvic or sacral bone localization had a normal scan. Bone scans made during treatment and more than 2 years thereafter in the 32 eligible patients demonstrated three patterns. In 16 patients the hot spot disappeared and no local tumor recurrence was encountered. In the other 16 patients the high uptake at the primary tumor site either persisted or diminished first to a normal uptake after a median period of 18 months (range 12-36 months) and returned again to a high uptake within 6-12 months. In these patients local Ewing's sarcoma was still present in 13, while in the other 3 cases a benign disorder (fracture, ectopic bone formation) was the underlying cause. These findings suggest that in non-surgically treated Ewing's sarcoma persisting increased tracer uptake or its recurrence is highly suspicious for the presence of Ewing's sarcoma, while bone scans becoming negative and remaining so for more than 12 months suggest the absence of local tumor.  相似文献   

19.
The aim of this phase II trial was to examine the efficacy of a new nitrosourea, cystemustine, in soft tissue sarcoma. Between January 1990 and March 1991, 32 pretreated patients with advanced soft tissue sarcoma were enrolled. Cystemustine was given every 2 weeks at 60 mg/m2 via a 15-min i.v. infusion. All eligible patients were considered evaluable for response and toxicity (WHO criteria). Of the 32 enrolled patients, 4 were ineligible, leaving 28 evaluable patients. All but 1 had been pretreated: 6 with adjuvant chemotherapy, 18 patients with first-line palliative chemotherapy without nitrosourea, 3 with both treatments, and 18 had received radiotherapy. Median age was 54 years (range 20-73) and median performance status was 1 (0-2). One partial response (PR, duration 12 weeks), 2 stable disease and 25 progressions were observed, giving an overall response rate of 3.57% (confidence interval: 0.1-18.4%). Toxicity was mild, and was mainly neutropenia (no grade 3 or 4), thrombocytopenia (3.57% grade 3 and grade 4) and nausea-vomiting (no grade 3 or 4). It should be noted that the treatment for the patient who obtained a PR was third line with no previous response. Cystemustine with this schedule appears to have a low clinical activity and toxicity in advanced soft tissue sarcoma.  相似文献   

20.
Quadriceps muscle strains are common sporting injuries, but occasionally a tear of the rectus femoris muscle can appear as a soft tissue mass of the anterior thigh with or without a significant history of trauma. Between 1992 and 1996, seven patients were referred to the Orthopaedic Oncology Unit at Walter Reed Army Medical Center with an unexplained soft tissue mass of the thigh. Three were active duty soldiers, three were military dependents, and one was a retired serviceman. All patients were men, and the mean age was 32 years (range, 15 to 73). A palpable, mildly tender mass was confirmed on clinical examination. Laboratory studies and plain radiographs were normal. Magnetic resonance imaging showed an obvious, but often ill-defined, lesion at the musculotendinous junction of the rectus femoris muscle. Four patients subsequently underwent a tissue biopsy to rule out a soft tissue sarcoma. Histologic studies showed fibrosis, degeneration of muscle fibers, and chronic inflammatory cells with no evidence of malignancy. A chronic rectus femoris muscle tear can mimic a soft tissue tumor or sarcoma and needs to be excluded in the differential diagnosis. These tears may occur acutely or may represent an overuse injury caused by repeated microtrauma. Careful history taking, physical examination, and selective radiographic studies, specifically magnetic resonance imaging, can confirm the diagnosis of muscle tear and full functional recovery can be anticipated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号